二氧化钼-碳复合涂层的电化学性能研究

Electrochemical Performance of MoO_2-C Composite Coatings

应用简单的刮涂法以及真空煅烧可制备出承载于铜箔表面的二氧化钼鄄碳(MoO_2-C)复合涂层,并对样品的形貌、成分、结构和电化学性能进行分析.结果表明,该复合涂层由单斜结构的MoO_2纳米粒子和无定形碳组成.一些MoO_2纳米粒子承载在碳基体表面,其尺寸为5~30 nm;一些MoO_2纳米粒子包覆在碳基体内部,其尺寸约为5nm.MoO_2-C复合涂层为多孔结构,其孔隙尺寸为1~3 nm.该复合涂层与铜箔结合紧密,界面处没有裂纹.承载在铜箔表面的MoO_2-C复合涂层的比容量高、循环和倍率性能良好.在100 mA·g^(-1)电流密度下,该负极经过100次循环后的比容量为814 mAh·g^(-1),在循环过程中没有出现明显的容量衰减.即使在5000 mA·g^(-1)的高电流密度下,其比容量仍有188 mAh·g^(-1).

The molybdenum dioxide-carbon（MoO2-C） composite coatings on the surface of Cu foils were prepared by a simple knife coating route and followed by sintering in vacuum. The morphology, composition, structure and electrochemical performance of the MoO2-C composite coatings were investigated. The results demonstrated that the MoO2-C composite coatings consisted of MoO2 nano-particles with monoclinic crystal structure and amorphous carbon. Some MoO_2 nano-particles with a size range of 5 ~30 nm were loaded on the surface of carbon matrices, while some MoO_2 nano-particles with a size of ~ 5 nm were encapsulated inside. The composite coatings showed porous structure with the pore size ranging 1 ~ 3 nm. The composite coatings attached firmly on the surface of Cu foils without any cracks occurred at their interface. The Cu-supported MoO2-C composite coatings delivered high capacity and good cyclic performance with a capacity of 814 mAh·g^（-1） at a current density of 100 mA·g^（-1） after 100 cycles without apparent capacity fading during cycling, and good rate performance with a capacity of 188 mAh·g^（-1） even at a high current density of 5000 mA·g^（-1）.